from tkinter import *
import time

root = Tk()
root.resizable(False, False)
root.geometry('300x100')
root.title('Часы')

time_text = Label(text = '', bg = '#999', width = 90, height = 90)

while True:
	time_text['text'] = time.strftime('%X')
	time_text.pack()
	root.update()